Container filling machine having feed screw with cylindrical bore forming member



March 18, 1952 4F. G. THOMPSON 2,589,583

.CONTAINER FILLING MACHINE HAVING FEED SCREW WITH CYLINDRICAL BORE FORMING MEMBER Filed May 25, 1947 FIG. i.

Inventor Farregt CiThompyon,

by my 'flttorneys hmforVd-hwcfofl Patented Mar. 18, 1952 UNITED STATES PATENT OFFICE CONTAINER FILLING MACHINE HAVING FEED SCREW WITH CYLINDRICAL BORE FORMING MEMBER 4 Claims.

This invention relates to new and useful improvements in filling machines, and more particularly to machines especially suited for filling containers with materials which are only partially flowable such as, for example, culture mediums for growing mushroom spawn.

In the production of mushroom spawn as generally practiced at the present time, a suitable culture medium or substrate composed, for example, of composted horse manure, tobacco stems, humus and similar materials, is packed into suitable containers, and a hole or bore is provided centrally through the medium to the bottom or closed end of the container. This medium is then innoculated through the mouth of the jar or container by placing the culture into the central hole or bore in the culture medium. The containers are then closed, for example, by plugs of cotton, using substantially surgical precautions to prevent contamination, and the containers are placed in a growing room where they are maintained at a temperature of about 70 F. until the growth of mycelium through the charge is complete, usually about 28 days.

Prior to the present invention these containers have been filled with the culture medium and the previously described hole or bore provided therein, in various ways. Usually, however, the container is filled with the culture medium by hand and then the hole or bore is drilled through the charge substantially to the bottom or closed end of the container. On the other hand, in many instances where substantially straightsided containers are employed, the filling, while still done manually, is accomplished by supporting the container with its mouth in register beheath a corresponding opening in a tableon which the culture medium is deposited, and a dowel of the desired diameter is positioned centrally within the container while the culture medium is deposited therein surrounding the dowel. As the filling operation proceeds, an annular temp of appropriate diameter, which is slidable upon the dowel, is used periodically to pack the culture medium firmly in the container about the dowel and, when the jar is completely filled with the culture medium, the dowel is withdrawn, leaving a bore or hole extending entirely through the culture medium.

The described manual procedures employed for filling containers with culture medium and providing the desired hole or bore therethrough are expensive and time-consuming, and the advantages to be gained by the use of a machine or apparatus which is operable to fill the containers and simultaneously form the hole or bore through the medium deposited therein, will be apparent.

With the foregoing in mind, the principal object of the present invention is to provide a novel machine or apparatus which is operable to fill a container with materials that are only partially fiowable such as, for example, culture mediums for mushroom spawn.

Another object of the present invention is to provide a machine or apparatus as set forth which is operable to fill a container with a mushroom spawn culture medium or other flowable material, and provide a passage or bore of predetermined diameter through the culture medium or material in the container.

Another object of the present invention is to provide a novel machine or apparatus as set forth which is operable to fill a container with a mushroom spawn or other flowable material and, at the same time, as filling of the container progresses, to form in the culture medium or other material a central passage or bore extending entirely, or at least a substantial distance, therethrough.

A further object of the invention is to provide a novel machine or apparatus having the aforesaid features and characteristics which is of relatively simplified construction and highly efficient and foolproof in operation and use.

These and other objects of the present invention and the various details of the construction and operation thereof are hereinafter fully-set forth and described with reference to the accompanying drawing, in which:

Fig. 1 is a sectional view vertically through filling apparatus made according to the present invention; and

Fig. 2 is an elevational view, in reduced scale, ofthe apparatus.

Referring now more particularly to the drawing, a machine or apparatus made according to the present invention may comprise a hopper l of generally V-shape in cross-section for containing a supply of a suitable partially fiowable material such as a mushroom spawn culture medium with which a container 0' is to be filled. The" hopper l at its lower end is provided with a discharge opening 2 of predetermined diameter which is defined by an annular flange portion 3 of the hopper. Connected by means of a suitable collar 4 to the hopper flange 3 is the upper end of a tubular delivery tube 5 which has a uniform internal diameter that conforms substantially to the diameter of the discharge opening 2 in the lower end of the hopper I. I

The delivery tube 5 depends vertically fro suitable source of power, for example, an electric motor (not shown). Connected to the shaft 6 and adapted to be rotationally driven thereby is a feed screw I which extends the entire'lengthof the delivery tube 5 and has its upper portion disposed within the lower portion of the hopper I. As shown in the drawing, the portion of the feed screw I within the tube 5 is of uniform diameter and the upper portion thereof increases' indiam eter as it extends upwardly into the lower portion of the hopper I. r

Preferably, the diameter of the portion of the feed screw I withinrthe delivery tube 5 is somewhat smaller than the internal diameter of'sai'd tube in' order to provide a small clearance between the screw I and internal wall of the tube for thepassage of larger than average particles ina culture medium such as, for example, pieces oftobacco stem, straw and the like, without jamming the feed screw. Similarly, in providing the increasing diameter of the upper portion of the feed screw I a good clearance is provided between the upper portion of said screw and the adjac'ent wall of the hopper I for the passage of a suitably configurated agitator device or the like 8 which may be mounted upon a shaft 6a arranged concentrically'about the shaft 6 and driven independently thereof.

, It is to' bel noted that the agitator 8 extends downwardly substantially to the neck or outlet openings. of the hopper I and in practice the agitator is rotationally driven at a considerably slower rate of speed than the screw 1. By increasing the diarneter of the feed screw I in the upper portion thereof within the hopper I, the culture medium, which is material that is only partially fiowable, is fed more positively to the delivery tube 5' and this arrangement, together with the described arrangement of the agitator 8 which prevents'jamming of the medium and insures a substantially constant rate of feed thereof from the hopper, makes it possible to feed effectively materials of only a partially flowable nature.

For the purpose of forming the hole or bore 9 in the culture medium deposited by the screw I in the container C, there is secured upon the lower or free end of the feed screw 1 coaxially thereof, a cylindrical element III of smaller diameter than the said feed screw and conforming, of course, to the diameter of the hole or bore 9 desired to be formed.

The container C to be filled is supported coaxially beneath the'delivery tube 5 upon "a support II which is fixed upon the upper end of a rod I2 that is adjustably mounted, for example; by a lock screw I3, in the vertically spaced arms I4 of a bracket I5. The bracket 5 is mounted for vertical sliding movement in guide ways I6 associated with a fixed part II of the m'achineor 7 apparatus, and is counterbalanced by means. of

band 22 having one end thereof anchored at 23 to the fixed part II of the machine. The band has its other end connected at 24 to the free end of a scale lever 25 which is pivotally mounted at its other end to said fixed part I! of the machine as indicated at 25 and has a weight 21 slidable thereon. By adjusting the position of the movable weight 21 upon the scale lever 25 the drag of the brake band 22 on the drum 2! may be increased or decreased to correspondingly vary the forces acting to oppose downward movement of the bracket I5 and the platform II with the result that resistance to the feed of material by the feed screw 'I into the container C likewise is" correspondingly increased or decreased to thereby control the density or compactness of the materials as packed into the container C.

In operation of. the apparatus, the container C to be filled is positioned upon the support II in alignment with the delivery tube 5 and the bracket I5 is moved upwardly to position the tube 5' within the container, the apparatus previously having been adjusted so that upward movement of the bracket I5 and support. II ceases, when the bottom or closed e'hd of the containerC is just about to engage the cylindrical elementIil' on the lower end of the feed screw 7; The weight 21 onth'e scale lever 25 is adjusted to give the required assistance to the feed of material according to the density or compactness thereof that may be desired. in the filled container and rotation of the shafts 6a and 6 is then-initiated to drivethe agitator 8. and the feed screw I :in' the direction indicated with the result that theculturemedium in the hopper I is conveyedrromthe latter through the delivery tube 5. and deposited thereby into the c ntainer C in surrounding relation to the cylindrical passage or bore forming element I8 carried by the screw 1 at the lower or free end thereof.

As filling of the container C progresses w h continuedrotation of the feed screw l, the container' C' and its support I! and associated bracket. 15'. are forced downwardly againstv the dragof thebrake band 22 by'the pressure exerted by the feed screw 1 upon the culture medium deposited thereby into the container. This action continues until the container C is filled tothe. depth desired and, as the container is forced downwardly as described, filling of the container progresses and the cylindrical element I0 carried at thefre'e'end of the feed screw I operates to form and maintain the bore or passage 9 in the culture medium as it is deposited into; the container C.

'Theam'ount of drag provided will depend upon the nature of the culture medium with which thecontainer C is filled as Well as upon the densltyor compactness of the culture medium desired inthe filled container. Thus, in cases where'git .is desired to pack the culture medium relatively loosely in the containers the brake or drag will be less than that employed in cases 'where'it is desired to pack the medium in a relative dense or compacted condition in the containers."

' From the foregoing it will be apparent that the present invention provides a novel machine or appa a t'us' whichis especially adapted for filling containers with partially 'fiowable materials such :fpr mushroom spawn and, at the same time, as

filling gi the container progresses to form in the material in the container a central bore or passage which extends entirely, or at least a substantial distance, therethrough. Furthermore, the invention provides a novel machine or apparatus having the aforesaid features and characteristics which is of relatively simplified construction and highly efficient and foolproof in operation and use.

While a particular embodiment of the invention has been shown and described herein, it is not intended that the invention be precisely limited to such disclosure and changes and modifications may be made therein and thereto within the scope of the following claims.

I claim:

1. In a container filling machine comprising vertically disposed container support means and a feed hopper relatively movable toward and away from each other between predetermined relatively adjacent and spaced apart positions, said hopper having its lower portion of inverted substantially frusto-conical shape and provided with an elongated delivery tube of uniform internal diameter depending from said hopper and arranged to extend into a container on said support in the relatively adjacent limit position of the latter and said hopper, a feed screw for delivering material from the hopper through said tube to a container on the support including a screw portion of uniform diameter extending entirely through said delivery tube and a screw portion of gradually increasing diameter 'disposed in the lower portion of the hopper, an agitator rotatable in said hopper independently of the feed screw and cooperable with the portion 0 thereof of increasing diameter to prevent jamming of the material and effect uniform feed thereof from the hopper to said delivery tube, and a cylindrical forming member of predetermined diameter at the delivery end of the feed screw operable to form a bore in the material deposited in the container.

2. In a container filling machine comprising a container support yieldably displaceable in a vertical direction between predetermined limit positions, means normally urging said container support to its upper limit position, a feed hopper disposed above said container support and provided with an elongated delivery tube of uniform internal diameter depending from said hopper and arranged to extend into a container on said support when said support is in its upper limit position, a feed screw including a portion of uniform diameter extending within said delivery tube having at its upper end a portion of gradually increasing diameter disposed in the lower portion of the hopper, said feed screw operating to effect a uniform feed of material from the hopper through the tube and into said container at a predetermined rate operable to displace downwardly the container and said support as the container is filled, and a cylindrical forming member of predetermined diameter carried by the feed screw at the delivery end thereof and operable to form a bore in the material deposited in the container as filling of the latter progresses.

3. In a container filling machin comprising a container support yieldably displaceable in a vertical direction between predetermined limit positions, means normally urging said container support to its upper limit position, a feed hopper disposed above said container support and provided with an elongated delivery tube of uniform internal diameter depending from said hopper and arranged to extend into a container on said support when said support is in its upper limit position, a feed screw including a portion of uniform diameter extendin within said delivery tube having at its upper end a portion of gradually increasing diameter disposed in the lower portion of the hopper, an agitator rotatable in said hopper independently of the feed screw and adjacent the portion thereof of increasing diameter, said feed screw and agitator cooperating to efiect a uniform feed of material from the hopper through the tube and into said container at a predetermined rate operable to displace downwardly the container and said support as the container is filled, and a cylindrical forming member of predetermined diameter carried by the feed screw at the delivery end thereof and operable to form a bore in the material deposited in the container as filling of the latter progresses.

4. In a container filling machine comprising a container support yieldably displaceable in a vertical direction between predetermined limit positions, means normally urging said container support to its upper limit position, a, feed hopper disposed above said container support, said hopper having its lower portion of inverted frustoconical shape and provided with an elongated delivery tube of uniform internal diameter depending from said hoppers and arranged to extend into a container on said support when said support is in its upper limit position, a feed screw including a portion of uniform diameter extending within said delivery tube having at its upper end a portion of gradually increasing diameter disposed in the lower portion of the hopper, an agitator rotatable in said hopper independently of the feed screw and adjacent the portion thereof of increasing diameter, said feed screw and agitator cooperating to effect a uniform feed of material from the hopper through the tube and into said container at a predetermined rate operable to displace downwardly the container and said support as the container is filled, a cylindrical forming memebr of predetermined diameter carried by the feed screw at the delivery end thereof and operable to form a bore in the material deposited in the container as filling of the latter progresses, and an adjustable brake acting to oppose downward movement of the container support and thereby control the compactness of the material placed in the container.

FORREST G. THOMPSON.

REFERENCES CITED The following references are of record in the 

